/*
 * ProGuard -- shrinking, optimization, obfuscation, and preverification of Java bytecode.
 *
 * Copyright (c) 2002-2018 GuardSquare NV
 *
 * This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public
 * License as published by the Free Software Foundation; either version 2 of the License, or (at your option) any later
 * version.
 *
 * This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied
 * warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License along with this program; if not, write to the Free
 * Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
 */
package proguard.classfile;

import proguard.classfile.visitor.*;

import java.util.*;

/**
 * This is a set of representations of classes. They can be enumerated or retrieved by name. They can also be accessed
 * by means of class visitors.
 *
 * @author Eric Lafortune
 */
public class ClassPool {
    // We're using a sorted tree map instead of a hash map to store the classes,
    // in order to make the processing more deterministic.
    private final Map classes = new TreeMap();

    /**
     * Clears the class pool.
     */
    public void clear() {
        classes.clear();
    }

    /**
     * Adds the given Clazz to the class pool.
     */
    public void addClass(Clazz clazz) {
        classes.put(clazz.getName(), clazz);
    }

    /**
     * Removes the given Clazz from the class pool.
     */
    public void removeClass(Clazz clazz) {
        removeClass(clazz.getName());
    }

    /**
     * Removes the specified Clazz from the class pool.
     */
    public void removeClass(String className) {
        classes.remove(className);
    }

    /**
     * Returns a Clazz from the class pool based on its name. Returns <code>null</code> if the class with the given name
     * is not in the class pool.
     */
    public Clazz getClass(String className) {
        return (Clazz)classes.get(className);
    }

    /**
     * Returns an Iterator of all class names in the class pool.
     */
    public Iterator classNames() {
        return classes.keySet().iterator();
    }

    /**
     * Returns the number of classes in the class pool.
     */
    public int size() {
        return classes.size();
    }

    /**
     * Applies the given ClassPoolVisitor to the class pool.
     */
    public void accept(ClassPoolVisitor classPoolVisitor) {
        classPoolVisitor.visitClassPool(this);
    }

    /**
     * Applies the given ClassVisitor to all classes in the class pool, in random order.
     */
    public void classesAccept(ClassVisitor classVisitor) {
        Iterator iterator = classes.values().iterator();
        while (iterator.hasNext()) {
            Clazz clazz = (Clazz)iterator.next();
            clazz.accept(classVisitor);
        }
    }

    /**
     * Applies the given ClassVisitor to all classes in the class pool, in sorted order.
     */
    public void classesAcceptAlphabetically(ClassVisitor classVisitor) {
        // We're already using a tree map.
        // TreeMap sortedClasses = new TreeMap(classes);
        // Iterator iterator = sortedClasses.values().iterator();

        Iterator iterator = classes.values().iterator();
        while (iterator.hasNext()) {
            Clazz clazz = (Clazz)iterator.next();
            clazz.accept(classVisitor);
        }
    }

    /**
     * Applies the given ClassVisitor to the class with the given name, if it is present in the class pool.
     */
    public void classAccept(String className, ClassVisitor classVisitor) {
        Clazz clazz = getClass(className);
        if (clazz != null) {
            clazz.accept(classVisitor);
        }
    }
}
